Keyboard



FIG. 1 is a front perspective view of a keyboard according to our design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a right-side view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a back view thereof; and,

FIG. 7 is a front view thereof.

The dashed broken lines in the figures depict portions of the keyboard that form no part of claimed design. 

CLAIM The ornamental design for a keyboard, as shown and described. 